Antihalo coating for photographic material



produce dyestufls for antihalo coatings.

Patented May 12, 1942 I UNITED STATES- PATENT OFFICE 2,282,890 ANTIHALO coa'rmo roa rno'rocaarmc MATERIAL Wilhelm Schneider and Richard Brodersen, Dessau, and Oswald Meissner and Max Ooenen, Uerdingen, Germany, assignors to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application May 14, 1940, Serial No. 335,142 In Germany March 28, 1939 4 Claims. (01. 95-8) This invention relates to antihalo oatings for be substituted at will, for instance by sulfoand photographic material. carboxyl groups.

It is known to provide panchromatic photo- For the production of antihalo coatings the graphic plates and films with green antihalo dyestuffs are either incorporated into colloids backings for anti-halation purposes. Malachite- 5 swelling in water, for instance gelatin, and the green, tetramethyl-L4-diaminotriphenylmethane solutions thus obtained are cast in a known manand similar compounds, mostly in the form of her as antihalo coatings underneath the emultheir sulfoor methane-sulfo acids, serve as sion-layer as shown in Fig. 1 of the accompanygreen dyestufis. The absorption maxima of all ing drawing or as antihalo backing layeron the these dyestuffs lie not far from the interval of back of the support for the photographic ma- 610640m which protects the sensitizing region terial as shown in Fig. 2 of the accompanying of the usual panchromatic sensitizers against drawing. Instead of the gelatin also other bindhalation. For the purpose of normal black-and- .ing agents, for instance resins soluble in alkali white photography these dyestufis are therefore according to U. S. Patent 2,089,764 may be apabsolutely sufficient. l5 plied. Admixtures may be given to the solution In order to obtain in color hotography absoaugmentin the stability and softness of the lutely correct color registration, it is sometimes layer. Films and foils consisting of cellulose denecessary to use sensitizers, the sensitizing maxrivatives, especially nitro and acetyl cellulose of ima of which lie beyond 650m For such purregenerated cellulose, synthetic structures, glass, poses the dyestuffs mentioned above are useless. etc., are likewise suitable as a support for the It is therefore an object of this invention to photographic material.

Another object is the provision of triphenyl- Example I methane dyestuffs for antihalo coatings absorb- In 0116 water are dissmved ing the light at least up to the wave length of 10 grams gelatin 700m 10 grams dyestuif of the following constitution:

A still further object is to provide such dyestuffs from antihalo coatings being derived from OEO G Q diphenylamine.

These and other objects will be seen from the detailed specification and examples following A hereinafter.

Our invention is based on the observation that for the purposes of antihalo coatings green tri- 30mg v phenylmethane dyestuifs may be advantageously employed which generally are obtained by con- 5 3 23 23 5 gig: gi l i i g g fig deltsmg two mols dlpherfylamme and n mol is opposite the emulsion layer and then dried. benzaldehyde' The f of these dyestuffs The antihalo coating thus obtained is effective lie according to substitution at BBQ-680m Conin spectral regions beyond 700ml trary to a great deal of other green triphenyl- 40 methane dyestuffs they have the advantage to Emmple H show a rather fiat absorption curve towards the In 15 liter alcohol are dissolved region of the long waves, which means, they are 30 able to still protect a spectral region beyond grams of soaped polymenzatmn Product 700m from vinylethylether and maleic acid anhydride according to U. S. Patent 2 161 788 All these d estufis are photographically free i i from harmfulyefiects They do not possess any 15 grams dyestufi of the following constitution: properties harmful to sensitivity, gradation and H sensitization and may be destroyed quickly and O' O Q O irreversibly in the photographic treating baths.

Also the combination of both dyestufi-types, i. e. diphenylamine dyestuffs containing nitro groups, may be employed with great advantage. An antihalo coating obtained from this solution The preparation of the dyestuifs is done accordhas an absorption maximum at about 670m, and ing to methods known in literature. They may an effective region until far into the ultra-r d,

It is easily soluble in alkaline baths, also in the antihalo coating comprising a dye corresponding developer. to the general formula: i

Example III x I In 1.5 liter alcohol are dissolved 5 Ri-N-C C C =YR:

50 grams of a condensation product from phenoxy acetic acid and formaldehyde 20 grams dyestufl of the following constitution:

ClhHl BIO-1k -N--CH: wherein c I R1 and R2 represent members of the group consisting of benzene and benzyl radicals, X stands for a member of the group consisting of hydrogen and alkyl, 6

Y stands for a bridge selected from the group consisting of tertiary and quaternary nitrogen atoms, and

N I Z stands for a member of the group consisting From this solution an antihalo coating with an of hydrogen. ni r lf nd xyl Gr absorption maximum at 660-665 ma and an anti- A P oto rap element P v ded with an halo eflfect up to above 700 m is obtained. on anti-halo ng p in a dye correspondaccount of the alkali solubility oi the binding 8 t0 the formula:

agent the layer disappears during the develop- H V Example IV In 1.5 liter alcohol are dissolved 50 grams of a condensation product from phenoxy acetic .acid and p-cresoldialcohol 50mm 15 grams dyestufi of the following constitution: A photographic element provided with an The antihalo coating obtained from this solution anti-halo 'coating comprising a dye correspondis eflective in spectral regions beyond 700 m ing to the formula: on account of the alkali solubility of the bind- H ing agent the layer disappears during the devel- -Q-NO =NOCOOH opment.

' Example V In 1 liter benzene 250 cc. acetone and 250 cc. 4- A photographic element provided with an alcohol are dissolved anti-halo coating comprising a dye correspond- 20 grams dyestufl of the following constitution: m t t formula;

4 grams camauba wax. The antihalo effect for go a film-backing obtained from this solution cor- WILHEIM SCHNEIDER- responds to Examples 1-4. RICHARD BRODERSEN. what we claim is; OSWALD MEISSNER.

1. a photographic element provided with an MAX COENEN- 

